This invention relates to an image information filing apparatus in which documents are recorded as image information on optical disks.
Recently, image information recording apparatus which record and reproduce great amounts of document data as image information have become extensively utilized. In such image information recording apparatus, documents are optically scanned and read out as image information. The read-out image information is recorded on an optical disk. At this time, retrieval data pertaining to the image information is also recorded on a recording medium, e.g., a floppy disk. When reproducing image information, a code corresponding to the retrieval data is keyed in. The retrieval data is thus searched from the floppy disk, and according to this floppy retrieval data the relevant image information is read out from the optical disk and displayed on a CRT display or printed out by a printer to produce a hard copy.
When image information is recorded on an optical disk in such information filing apparatus, it is usually data compressed for each scanning line by a MF (modified Hoffman) coding method or MR (modified Reader) coding method before it is recorded on the optical disk. In most cases, the quantity or length of compressed data varies for each scanning line. That is, data lines of different lengths are continuously arranged. For this reason, it is difficult to separate the data lines from each other.